268 research outputs found
Amplified spontaneous emission in the spiropyran-biopolymer based system
Amplified spontaneous emission (ASE) phenomenon in the 6-nitro-1′,3′,3′-trimethylspiro[2H-1-benzopyran-2,2′-indolin] organic dye dispersed in a solid matrix has been observed. The biopolymer system deoxyribonucleic acid blended with cationic surfactant molecule cetyltrimethyl-ammonium chloride served as a matrix. ASE appeared under sample excitation by UV light pulses (λ=355 nm) coming from nanosecond or picosecond neodymium doped yttrium aluminum garnet lasers and has been reinforced with green (λ=532 nm) light excitation followed UV light pulse. The ASE characteristics in function of different excitation pulse energies as well as signal gain were measured
Biopolymer-based material for optical phase conjugation
We present results of optical phase conjugation experiments in modified DNA (deoxyribonucleic acid) - dye system. The system consisted of a biopolymeric matrix made of DNA blended with cationic surfactant molecule cetyltrimethyl-ammonium chloride (CTMA) and doped with a photochromic dye Disperse Red 1. Results were obtained in a typical degenerate four wave mixing experiment. For sample excitation we used linearly polarized light at a wavelength 514.5 nm, delivered by an argon ion (Ar+) laser. The phase conjugated signal which emerged from the sample had rise and fall time constants of a few milliseconds with an excellent reversibility
Influence of surfactant on dynamics of photoinduced motions and light emission of a dye-doped deoxyribonucleic
Pure deoxyribonucleic acid (DNA) is known to be soluble in water only and exhibits poor temperature stability. In contrary, it is well known that the complex of DNA - with cetyltrimethyl ammonium (CTMA) is insoluble in water but soluble in alcohols and can be processed into very good optical quality thin films by solution casting or spin deposition. Despite the success of DNA-CTMA, there is still need for new cationic surfactants which would extend the range of available solvents for DNA complex. We test and present experimental results of influence of new surfactants replacing CTMA in the DNA complex and based on benzalkonium chloride (BA) and didecyldimethylammonium chloride (DDCA) on their optical properties. Particularly, we were interested in all optical switching and light generation in amplified spontaneous emission process in these materials
Amplified spontaneous emission of Rhodamine 6G embedded in pure deoxyribonucleic acid
Deoxyribonucleic acid (DNA) is commonly viewed as a genetic information carrier. However, now it is recognized as a nanomaterial, rather than as a biological material, in the research field of nanotechnology. Here, we show that using pure DNA, doped with rhodamine 6G, we are able to observe amplified spontaneous emission (ASE) phenomenon. Moderate ASE threshold, photodegradation, and reasonable gain coefficient observed in this natural host gives some perspectives for practical applications of this system in biophotonics. Obtained results open the way and will be leading to construction of truly bio-lasers using nature made luminophores, such as anthocyanins
An algorithm for decoherence analyses of lights through three-dimensional periodic microstructures
A transfer-matrix algorithm is presented herein as a beginning to study the
transmission characteristics of coherent light through three-dimensional
periodic microstructures, in which the structures are treated as
two-dimensional-layer stacks and multiple reflections are considered
negligible. The spatial-correlated noise is further introduced layer by layer
to realize the actual decoherence of the light and allows for statistical
investigation of the partial spatially coherent optics in transparent mediums.
Numerical analyses show comparable results to the Gaussian Schell model in
free-space cases, indicating the validity of the algorithms.Comment: 15 pages, 7 figure
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